How to resolve Git merge conflicts in 8.0.2?

In previous versions of phpStorm I had no issues resolving merge conflicts. I forget excactly how I used to open the conflict resolution dialog, but I think it was in the VCS menu and was easy to find.

I tried making a commit through GitHub on my PC and there is a merge conflict. I've probably been trying for half an hour, but simply cannot figure out how to get to the conflict resolution tool in 8.0.2 -- it just doesn't seem to exist anymore!

I tried going to VCS -> Git -> Merge Changes, and I see this dialog:



I don't understand what the first branch is, but I've tried selecting them individually and both together at the same time and then click Merge, but it results in this:



Where did the conflict resolution tool go? What am I doing wrong? How do I resolve merge conflicts for Git in 8.0.2?